全文获取类型
收费全文 | 460篇 |
免费 | 16篇 |
国内免费 | 20篇 |
专业分类
化学 | 23篇 |
晶体学 | 6篇 |
力学 | 102篇 |
综合类 | 4篇 |
数学 | 305篇 |
物理学 | 56篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 19篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 56篇 |
2012年 | 14篇 |
2011年 | 15篇 |
2010年 | 19篇 |
2009年 | 38篇 |
2008年 | 27篇 |
2007年 | 39篇 |
2006年 | 20篇 |
2005年 | 25篇 |
2004年 | 24篇 |
2003年 | 26篇 |
2002年 | 22篇 |
2001年 | 12篇 |
2000年 | 8篇 |
1999年 | 18篇 |
1998年 | 10篇 |
1997年 | 14篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有496条查询结果,搜索用时 15 毫秒
1.
Héctor J. Sussmann 《Set-Valued Analysis》2002,10(2-3):233-285
It is shown that the construction of needle variations can be carried out for almost lower semicontinuous differential inclusions rather than for the case of ordinary single-valued continuously differentiable vector fields usually considered in the literature. The construction leads to needle variations whose flows are in general set-valued but still have good differentiability properties. The variations are constructed by using single-valued selections that are not necessarily continuous with respect to the state variable, but have instead a much weaker 'integral continuity' property, somewhat more general that the 'directional continuity' considered in previous work by A. Cambini and S. Querci, A. Pucci, and A. Bressan. The existence of many such selections is proved by slightly adapting an argument due to Bressan, extending it from the lower semicontinuous to the almost lower semicontinuous case, and strengthening it to yield not only directional continuity at all points but also full continuity at a specified point. 相似文献
2.
In this paper we prove existence results for semilinear neutral functional differential inclusions with finite or infinite
delay in Banach spaces. Our theory makes use of analytic semigroups and fractional powers of closed operators, integrated
semigroups and cosine families.
相似文献
3.
Tiziana Cardinali Raffaella Servadei 《Proceedings of the American Mathematical Society》2004,132(8):2339-2349
In this paper we obtain the existence of periodic solutions for nonlinear ``invariance' problems monitored by impulsive differential inclusions subject to impulse effects.
4.
Controllability of Functional Integro-Differential Inclusions with an Unbounded Delay 总被引:1,自引:0,他引:1
In this paper, a sufficient condition is established for the controllability of neutral functional integro-differential inclusions
with an unbounded delay in Banach spaces. The approach used is a fixed-point theorem for condensing maps due to Martelli and
the theory of analytic semigroup of linear operators.
Communicated by F. Zirilli
Research supported by NNSF of China, by the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education
Institutions of the Ministry of Education of China, and by the Qing Lan Talent Engineering Fund QL-05-164 of Lanzhou Jiaotong
University. The authors are grateful to Professor F. Zirilli and two anonymous referees for valuable suggestions improving
this paper. 相似文献
5.
In this paper a class of impulsive differential inclusions is investigated. The existence of solution bundle is proved. And we also construct a nonlinear semigroup of operators on cb(E) (closed-bounded subset of E) to describe the set of attainable states. 相似文献
6.
7.
First order dynamic inclusions on time scales 总被引:1,自引:0,他引:1
F.Merdivenci Atici D.C. Biles 《Journal of Mathematical Analysis and Applications》2004,292(1):222-237
In this paper, we study existence of solutions of first order dynamic inclusions on time scales with general boundary conditions. Both the ∇-derivative and Δ-derivative cases are considered. Examples are presented to illustrate that the Δ-derivative case needs more restrictive assumptions. 相似文献
8.
Tzanko Donchev 《Journal of Mathematical Analysis and Applications》2004,299(2):525-533
One from the most important properties of accretive and monotone operators is the existence of zeros and surjectivity. In the paper we introduce relaxed variants of dissipative, accretive and monotone operators. Using essentially the properties of the solution set of appropriate differential inclusions we study the existence of zeros of such operators. As corollaries the existence of fixed points of relaxed contractive and relaxed nonexpansive multifunctions are obtained. 相似文献
9.
A. A. Tolstonogov 《Set-Valued Analysis》1998,6(2):129-147
Existence theorems of continuous selectors whose values are fixed points of multivalued contractions are proved. As an application, the existence of continuous selectors to generalized solution sets of partial differential inclusions, depending on a parameter, is obtained. 相似文献
10.
N. V. Kas’yan A. V. Shvets S. A. Sergienko V. G. Il’in 《Theoretical and Experimental Chemistry》2006,42(4):255-259
The zeolite IPC-3, isomorphous with germanate zeolite ASU-16, and its silicon, aluminum, and titanium analogs, were obtained
in the presence of 1,6-diaminohexane as a template. It is possible to incorporate selectively the elements in different crystallographic
positions, determined by the nature of the element, particularly its valency and its coordination number with respect to oxygen.
Silicon takes tetrahedral positions in the IPC-3 lattice, Al either tetrahedral or octahedral positions, and Ti octahedral
positions. Small amounts of the lithium cations facilitate tetrahedral coordination and increase the Al content in IPC-3.
__________
Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 4, pp. 246–251, July–August, 2006. 相似文献